1. Field of the Invention
The invention relates to scramblers for TV video signals and more particularly to scramblers using serial memories which are preferably charge coupled devices.
2. Description of the Prior Art
Scramblers for TV signals which interchange portions of the video information to scramble the signal are well known in the art. Typical examples of such scramblers and related apparatus are disclosed in U.S. Pat. Nos. 3,872,503 and 4,266,243. All of these patents are assigned to the same assignee as the current application. In these prior art systems the video signal was first sampled to generate digital numbers representative of the amplitude of the video signal. These digital numbers were stored in a digital memory. Sufficient memory was provided to store digital numbers representing at least two scan lines of the video signal. The stored data was then read with the beginning and end portions of the video signal corresponding to a scan line interchanged on a random basis to scramble the TV signal. Although these systems functioned for their intended purpose the hardware was more complex than the scrambler which is the subject of this invention.